(1) “Abandoned workings,” excavations, either caved or sealed, that are deserted and in which further mining is not intended.

(2) “Active workings,” all places in a mine that are ventilated and inspected regularly.

(3) “Anthracite mine,” shall include any coal mine not now included in the bituminous boundaries.

(4) “Approved,” which is used in connection with equipment, supplies, explosives and lamps, means “approved for use in anthracite mines by the secretary,” whether such approval has been made prior to or subsequent to the effective date of this act.

(5) “Coal mine or colliery,” includes every operation and work, both underground and above-ground, used or to be used for the purpose of mining and preparing coal.

(6) “Department,” the Department of Mines and Mineral Industries¹ organized and operating in the Commonwealth of Pennsylvania, hereinafter referred to as the “department.”

(7) “Deputy Secretary of Mines and Mineral Industries,” a person appointed by the secretary, with the approval of the Governor, to assist and aid the secretary in carrying out the provisions of this act, hereinafter referred to as the “deputy secretary.”

(8) “Drift,” a horizontal passageway driven from the surface in the coal seam used for the same purposes as a shaft or slope.

(9) “Electrical inspector,” the person commissioned by the Governor to perform electrical inspections as hereinafter prescribed.

(10) “Face,” defined as being the solid coal or rock at the inby end of a working place.

(11) “Gassy mine,” an anthracite coal mine where methane has been ignited therein; or has been detected therein with an approved flame safety lamp, or an approved methane detector; or by laboratory analysis of a sample of air, taken not less than twelve inches from the roof, face and rib, containing methane in an amount of twenty-five one hundredths percent or more.

(12) “Intake air,” shall be considered a volume of fresh air being conducted toward the interior of a mine before it contacts the first working place in any particular air split.

(13) “Investigating commission,” (hereinafter referred to as a commission), shall consist of a group of at least three mine inspectors or electrical inspectors, or a combination of both, appointed by the secretary for the purpose of investigating and reporting on any problem in question in compliance with the provisions contained in this act. The district mine inspector shall accompany and commission in his district but need not be a member thereof. The secretary, at his discretion, may appoint the deputy secretary as a member of any commission.

(14) “Main doors,” which are erected in sets of three, mean those which if left open or removed will interrupt or destroy the ventilating current on the split in which they are located or in any other split in the mine.

(15) “Mine,” includes all underground workings and excavations, and shafts, tunnels and other ways and openings; also all such shafts, slopes, tunnels and other openings in course of being sunk or driven, together with all roads, appliances, machinery and material connected with the same below the surface. The term “mine” shall not include any strip mine.

(16) “Mine examiner,” shall mean any certified person designated to examine a mine for gas and other dangers. The title “mine examiner,” as used in this act, is synonymous with the title “fire boss,” as heretofore understood.

(17) “Mine foreman,” the person whom the operator or superintendent shall place in charge of the inside workings of the mine and of the persons employed therein.

(18) “Mine inspector,” the person commissioned by the Governor to have supervision of mines as hereinafter prescribed.

(19) “Miner,” the person who cuts or blasts coal or rock at the face of a gangway, airway, breast, chamber, pillar, tunnel, drift, or other working place; also any person engaged at general work in a mine, and qualified to do the work of a miner.

(20) “Non-gassy mine,” any anthracite coal mine which has not been classified as gassy.

(21) “Operator,” any firm, corporation, or individual, operating any coal mine, or any part thereof.

(22) “Owner,” means any person or body corporate who is or becomes the owner of the coal recovered as the result of deep mining. The term “owner” does not include a person or body corporate who receives a royalty, rent or fine from a coal mine or colliery, or part thereof, or is the proprietor of a mine subject to any lease, grant or license for the working or operating thereof.

(23) “Permissible” means any equipment, device or explosive that has been approved as such by the United States Bureau of Mines, whether such approval has been made prior to or subsequent to the effective date of this act.

(24) “Permissible equipment,” when used herein, shall mean such equipment tested and approved by the United States Bureau of Mines, whether such approval has been made prior to or subsequent to the effective date of this act, and providing that the same is installed, maintained and used in accordance with the conditions prescribed by the bureau.

(25) “Preparation plant,” a breaker, washery or other plant, where run-of-mine anthracite from mines and strippings, or anthracite from refuse banks, is processed by crushing, washing, screening and the removal of impurities to make the same suitable as a fuel.

(26) “Return air,” after a volume of air has ventilated one or more places in “active” or “abandoned working” it shall be designated as return air.

(27) “Secretary of Mines and Mineral Industries,” the head of the Department of Mines and Mineral Industries, appointed and commissioned by the Governor, hereinafter referred to as the “secretary.”

(28) “Shaft,” means a vertical opening through the strata that is or may be used for the purpose of ventilation or drainage, or for hoisting men or material, or both, in connection with the mining of coal.

(29) “Shall,” where used herein is understood to be mandatory and the word “should” advisory.

(30) “Slope” means any inclined way or opening used for the same purpose as a shaft.

(31) “Superintendent,” the person who shall have, on behalf of the operator, general supervision of one or more mines or collieries.

(32) “Working place,” means the face area of a gangway, airway, breast, chamber, cross heading, pillar, tunnel, drift, or other place where coal or rock is being removed or any place that is being prepared for the removal of coal or rock.

(33) “Workings,” includes all the excavated parts of a mine, those abandoned as well as the places actually at work.